The present invention relates generally to supports used for creating cured pre-cast panels and related structures, and more specifically to the configuration of extensions used to create recesses at panel edges and apertures that are used to define windows, doorways and related openings in the panel.
Many residential and commercial construction methods involve the use pre-cast structures. Pre-cast panels, for example, are integral to the tilt-up construction process. In the tilt-up approach, concrete forms are arranged on a flat casting surface in the shape and dimension of the desired tilt-up panel, then filled with concrete. When the concrete cures, the panel and the form are separated and the panel is tilted up into a preferred, typically vertical, orientation, where it can be joined to structural frames or other panels. The present inventors have recognized a need for improvements in pre-cast panel forming systems and in various components of the panel forming systems. The improvements introduced by the present invention have applicability in the tilt-up construction process and in other pre-cast construction processes.
This need is met by the present invention wherein improvements in pre-cast panel forming systems and in various components of the panel forming systems are introduced. In accordance with one aspect of the present invention, a panel-forming system is disclosed. The panel-forming system includes a plurality of bulkheads and at least one aperture extension. The bulkheads and aperture extensions are placed on a panel-forming surface. In the present context, the bulkheads and aperture extensions are placed xe2x80x9conxe2x80x9d a panel-forming surface, which is meant to be broadly construed, thus encompassing situations where both direct contact between the panel-forming surface (which may be, for example, a smooth floor) and the bulkheads and aperture extensions, as well as indirect support (where, for example, a release liner may be placed over the panel-forming surface prior to arrangement of the bulkheads or aperture extensions) are contemplated. The bulkheads include a first group and a second group, where the first group is arranged into the shape of the panel to be formed, while the second group is disposed substantially within a shape formed by the first group. In the present context, the term xe2x80x9csubstantiallyxe2x80x9d is utilized to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. As such, it refers to an arrangement of elements or features that, while in theory would be expected to exhibit exact correspondence or behavior, may, in practice embody something slightly less than exact. The term also represents the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue.
Upon formation of a panel (such as by pouring an uncured panel-forming material, for example, concrete into the dimensions bounded by the two bulkhead groups), the space that is substantially surrounded by the second group defines an aperture in the panel. The aperture extension includes a bulkhead-engaging portion configured to contact the bulkhead; and a recess portion extending laterally from the bulkhead-engaging portion such that upon formation of the panel, a pattern becomes defined therein by surfaces on the aperture extension that are configured to face the panel, the recess portion defining a height dimension and an elongate lateral dimension extending from a proximal end to a distal end, the proximal end disposed closer to the bulkhead-engaging portion than the distal end, the elongate lateral dimension being substantially greater than the height dimension. In the present context, the aspect ratio of the aperture extension is defined as the ratio of the height of the portion of the extension that faces the formed panel to the lateral (horizontal) extension of the portion of the extension that faces the formed panel. Thus, in contrast to conventional panel-forming systems that merely include a chamfer designed to create a bevelled recess near a panel edge that is defined by an aspect ratio of unity or thereabouts, the device of the present invention contemplates myriad recess transition possibilities, including long, gradual recesses and multifaceted recesses, which taken alone or together provide the panel designer with numerous functional and aesthetic options.
Optionally, the recess portion further comprises at least one chamfer disposed at the terminus of at least one of the proximal and distal ends. A base clip disposed along at least a part of the recess portion may also be included. In one configuration, the base clip is integrally formed with the recess portion. Preferably, the recess portion is defined by an aspect ratio of less than 0.5, and more preferably less than 0.2, and even more preferably less than 0.1, such that it is considerably wider than it is tall. In another option, the bulkhead-engaging portion and the recess portion together define a unitary (one-piece) construction, while in another the bulkhead-engaging portion and the recess portion are formed as discrete components. In configurations where the bulkhead-engaging portion and the recess portion are formed as discrete components, at least one end of the bulkhead-engaging portion terminates in a chamfer. In addition, the surface of the recess portion that is configured to face the panel can be multi-faceted to define complementary multifaceted surfaces on the portion of the panel adjacent the recess portion. In yet another option, an extension cap is included to engage the distal end of the recess portion. This extension cap effectively widens the lateral dimension of the aperture extension. The upper surface of the extension cap and the recess panel are preferably made to form a substantially seam-free planar surface, thus resulting in fewer seams on the formed panel. In addition, the extension cap comprises one or more notches that define a line of weakness therein to facilitate removal of at least a portion of the extension cap. These notches provide a convenient breakaway point such that the user can select a predetermined lateral length from which to work. In one form, the notches are spaced substantially equidistant from one another. In addition, the extension cap can include a base clip portion disposed adjacent its distal end. This base clip can be used to secure the aperture extension to the panel-forming surface. The base clip may further include frictional engaging members to attach the extension clip to, among other things, the recess portion of the aperture extension. A notch may be disposed between the base clip and the remainder of the extension cap, and as before, define a line of weakness therein to facilitate removal of the base clip. At least one frictional engagement member may be disposed between the extension cap and the recess portion to effect a secure connection between them. All of the aforementioned frictional engagement members may be made up of a plurality of prismatic members. A seal may be disposed substantially at a distal end of the extension cap. In one form, this seal can create a knife-edge along the panel-forming surface so that gaps between the extension cap and the panel-forming surface are eliminated or minimized. This inhibits the undesirable seepage of uncured panel-forming material (such as concrete, for example) into the underside of the aperture extension.
In another option, the aperture extension includes at least one stiffening rib disposed along the recess portion. As with the extension cap, a base clip may be configured to frictionally engage one or more of the stiffening ribs. This can help secure the recess portion to other structure, such as the panel-forming surface. Also as before, the frictional engagement between the base clip and the stiffening rib may comprise a plurality of prismatic members. These are disposed on coupling surfaces of the clip and the rib. In another option, an intermediate can be used to engage the distal end of the recess portion, where an extension cap similar to that previously discussed can engage the intermediate. This allows even longer extension of the aperture extension. As with the recess portion and the extension cap, a base clip may be included to frictionally engage the intermediate, where prismatic members disposed on coupling surfaces of the clip and the intermediate may be used to establish frictional fit. The base clip can be integrally formed with the recess portion, with at least one end of the intermediate. In the latter case, a notch may be disposed between the base clip and the remainder of the intermediate. As with the previously-described notches, these facilitate quick removal along score lines defined by the notches. The intermediate may assume various shapes (such as a chamfer portion) at one or both of its ends. Similarly, the extension cap may comprise a chamfer portion or similar shape at its terminus.
In yet another option, the aperture is surrounded in its entirety by the second group such that a window or door is defined therebetween. To facilitate angled joining at the aperture corners, some of the aperture extensions are configured as multifaceted recess corner sealing device, each comprising a bulkhead-engaging portion and a recess portion. Each multifaceted recess corner sealing device includes a substantially upstanding face disposed along a longitudinal dimension thereof. The multifaceted recess corner sealing devices are configured to be disposed substantially parallel to one another along at least a portion of the second group of bulkheads, where their substantially upstanding faces are configured to project at least as far in a vertical dimension as the taller of the bulkhead-engaging portion and the recess portion of the aperture extensions discussed in the previous aspects of the invention. Upon arrangement of the two types of aperture extensions against the second group of bulkheads, the earlier-described ones are configured to be disposed substantially parallel to one another and substantially perpendicular to multifaceted recess corner sealing device variants such that an end portion of each of the earlier-described aperture extensions abut the substantially upstanding face of the multifaceted recess corner sealing device such that upon introduction of uncured panel material into the recessed panel forming system, the leakage of the uncured panel material into surfaces of the aperture extension opposite the surfaces configured to face the panel is inhibited. In addition, the second group of bulkheads is configured to define more than one aperture in the panel. In a further option, the plurality of apertures in the panel are substantially aligned along at least one edge with one another. Moreover, the multifaceted recess corner sealing devices extend at least the substantial entirety of the length defined by the apertures, and more preferably, the substantial entirety of the length of the panel being formed. In configurations where the multifaceted recess corner sealing devices do not extend the entire length of the panel, their open ends can be plugged with an optional end cap to prevent uncured panel-forming material from flowing into the device cavities. The multifaceted recess corner sealing devices can arranged in a parallel on opposite sides of a generally rectangular aperture such that the substantially upstanding faces face each other.
According to another aspect of the invention, a panel-forming system is disclosed. The system includes a plurality of bulkheads configured to be placed on a panel-forming surface, and at least one aperture extension. The bulkheads are configured similar to those previously discussed. The aperture extension includes a bulkhead-engaging portion and a multifaceted recess portion, the latter of which extends laterally from the bulkhead-engaging portion such that upon formation of the panel, a pattern becomes defined in the panel by surfaces on the aperture extension that are facing the material placed in the panel-forming system. The multifaceted recess portion includes a height dimension, an elongate lateral dimension extending from a proximal end to a distal end, and a longitudinal dimension mutually orthogonal to both the height and lateral dimensions. Optionally, the multifaceted recess portion includes a substantially upstanding face disposed along a longitudinal dimension thereof such that the multifaceted recess portions can be disposed substantially parallel to one another along at least a portion of the second group of bulkheads. Preferably, the multifaceted recess portions are configured to project at least as far in a vertical dimension as the taller of the bulkhead-engaging portion and the recess portion of the aperture extensions mentioned previously. In yet another option, each facet on the multifaceted recess portion is orthogonal to its immediate neighbor, thereby defining a box-like structure. As with the previously-described aspects of the invention, a notch may be included on at least one surface of the aperture extension, the notch configured to facilitate breakaway removal of a portion of the aperture extension from its remainder. Also as before, the aperture extension may be of unitary construction. In another option, an edge seal may be disposed along the longitudinal dimension of the aperture extension. This seal may be along one or more of the corners formed by the various faceted surfaces, and can be made from a soft, resilient material, such as soft polyvinyl chloride. These seals help prevent leakage.
According to another aspect of the invention, an aperture extension and a multifaceted recess corner sealing device, both for use in a panel-forming system, are disclosed. The aperture extension is configured similar to that of the previously-discussed aspects, including a bulkhead-engaging portion and a recess portion. Similarly, the multifaceted recess corner sealing device is as previously discussed. Moreover, the aperture extension and a multifaceted recess corner sealing device can be used either separately or in conjunction with one another.
According to another aspect of the invention, a method of forming an aperture in a panel for tilt-up construction is disclosed. The method comprises the steps of arranging a plurality of bulkheads on a casting surface to form a mold, configuring an aperture extension to comprise a bulkhead-engaging portion and at least one recess portion extending laterally from the bulkhead-engaging portion, coupling the aperture extension to at least one bulkhead from the second group, and pouring uncured casting material into a mold defined by the bulkheads such that, upon formation of a panel with dimensions bounded by the first group and the second group, an aperture becomes defined in a space substantially surrounded by the second group. The bulkheads comprise a first group and a second group, where the first group is arranged in the shape of a panel to be formed, and the second group arranged such that it is substantially disposed within the shape formed by the first group. A pattern becomes defined in the panel by surfaces on the aperture extension that are configured to face the panel. The recess portion defines a height dimension and an elongate lateral dimension, the latter extending from a proximal end to a distal end, where the proximal end is disposed closer to the bulkhead-engaging portion than the distal end. The lateral dimension is substantially greater than the height dimension. Optionally, the method may include the additional steps of curing the casting material and removing the bulkheads and aperture extension from the panel.